Career Goals: This is an application for a K01 Career Development Award in Population Research for Ushma Upadhyay, PhD, MPH, a Public Health Social Scientist at the University of California, San Francisco. Her preliminary research focuses on contraceptive use and unintended pregnancy, and includes the development of the first measure of reproductive autonomy, assessing a woman's power to decide about and control matters related to contraceptive use, pregnancy and childbearing. In the short term, she aims to build on this work, investigating the effect of gender-based power on contraceptive use among young people. In the long term, she aspires to conduct research that results in evidence-based interventions that help young people to control their fertility. The knowledge and experience she will gain from the K01 award will prepare her to compete for NICHD R01 funding to design a randomized intervention trial to test the effects of a gender-based power intervention on contraceptive use and unintended pregnancy among adolescents and young people. Environment: The University of California, San Francisco (UCSF) provides generous support for junior faculty. UCSF researchers have a long history of pursuing innovative ideas in reproductive health. As an institution, it has been unequivocally supportive of research on contraceptive use and unintended pregnancy. Key Elements of Research Career Development Plan: Dr. Upadhyay has a rich background in epidemiologic and demographic methods, with substantial experience analyzing large datasets. This career development award will enable her to address several remaining gaps in her training specific to her career goals, and to gain applied experience planning and executing a primary data collection study on gender-based power and contraceptive use. Her training goals are to gain experience and expertise in sociological theories of gender among adolescents, qualitative research, advanced quantitative methods, and translating evidence into intervention. To achieve these goals, Dr. Upadhyay has assembled a unique interdisciplinary training and mentoring team. It includes a Primary Mentor, Tina Raine-Bennett, MD, MPH, a clinician scientist formerly at UCSF who is now Research Director of the Women's Health Research Institute at Kaiser Permanente specializing in adolescent unintended pregnancy and racial disparities, and co-mentor Shari Dworkin, PhD, MS, a medical sociologist in UCSF's Department of Social and Behavioral Sciences and an expert on gender- based power. Her team includes three additional, complementary advisors: Diana Foster, PhD, a demographer in UCSF's Department of Obstetrics, Gynecology, and Reproductive Sciences, who studies the consequences of unintended pregnancy; Torsten B. Neilands, PhD, a quantitative methodologist at UCSF's Center for AIDS Prevention Studies with expertise in latent variable (structural equation) modeling; and Claire Brindis, DrPH, Professor of Pediatrics and Health Policy whose research focuses on adolescent and child health policy, adolescent pregnancy and pregnancy prevention, and adolescent health and risk-taking behaviors. Dr. Upadhyay's training will include a combination of structured reading lists and tutorials with mentors, coursework, self-directed learning, conference presentations and attendance, and seminars. Description of the Research Project: Unintended pregnancy is an important public health problem; half of all pregnancies in the United States are unintended. The transition to adulthood is a particularly vulnerable period for unintended pregnancy; women ages 15 to 24 are at highest risk. One of the main reasons for unintended pregnancy is lack of consistent contraceptive use. The overall objective of this study is to conduct mentored research that examines the pathways between power, gender norms, and masculinities and contraceptive use among young people ages 15 to 24. My main hypothesis is that adherence to gender norms and traditional norms of masculinity lead to inconsistent and non-use of contraceptives. This research will assess this hypothesis through three specific aims. Aim 1 is to explore the role that relationship power, gender norms, and masculinities have in influencing adolescent and young people's contraceptive use. This aim involves qualitative in-depth interviews with adolescent and young women, men, and couples. Aim 2 is to adapt and validate existing instruments that measure relationship power, gender norms, and masculinities so that they are appropriate for adolescents and young people. This aim involves adapting my own Reproductive Autonomy Scale, the Gender Relations Scale, and the Masculinity Ideology in Relationships Scale for use among adolescents and young men and women. Aim 3 is to determine how relationship power, gender norms, and masculinities impact adolescent and young people's contraceptive use through a 3-month pilot prospective study at an adolescent family planning clinic. Examining gender-based power from the perspectives of multiple disciplines using mixed-methods, I expect to make important contributions in three areas: 1) theory on gender and power and contraceptive use, 2) measurement of gender-based power among adolescents, and 3) potential interventions that reduce unintended pregnancy. Ultimately, this mentored research will prepare me for the successful submission of an R01 application to test an adolescent contraceptive use intervention and a research career in gender and power-related determinants of adolescent reproductive health.